Researchers at Oregon Health & Science University say that people who eat diets high in trans fat were more likely to experience "brain shrinkage" than those who eat a health diet low in trans fats. Just a reminder: Trans fats, listed on ingredient labels as "partially hydrogenated" oils, are often found in packaged cookies and cakes, fast food, and many margarine spreads. (And, I found trans fat lurking in the strangest place!)

You may be able to ward off a shrinking brain and diseases like Alzheimer's by eating more vegetables, foods high in vitamins E, D, C and A, and getting plenty of omega-3 fatty acids, say the researchers.